4 ms·

Most likely scenario I can imagine: While everything was TLS encrypted between all conversation participants and the Snapchat server (airport Wi-Fi is a non-se

Most likely scenario I can imagine: While everything was TLS encrypted between all conversation participants and the Snapchat server (airport Wi-Fi is a non-sequitur here), Snapchat has some kind of PRISM-style setup that at least starts with a global keyword scanner for natsec-related triggers. That alone seems unlikely to have resulted in fighter jets scrambling. More likely, that keyword system feeds into a much more complex Palantir deployment or something that's cross-referencing a bunch of other factors and assigning a risk score. In this case, it was enough to get flagged for immediate review, someone thought the contextual elements were enough to escalate, and this set off a chain of actions leading to the fighter jets. There are likely thousands of terrorism jokes made over back-doored messaging systems every day, but sending one of those messages buys you a lottery ticket you certainly don’t want to win.

whatshisface 3y ago
You seem to know a lot about security for someone with no interest in evading it. Good luck with your lottery ticket...
dogma1138 3y ago
Snapchat does not encrypt text messages only photos and video. Also the question of how many of those joke messages are being sent from an airport and have account meta data that can be tied to travel information (name, email, phone number). I wager far fewer that it may not make it into as much of a game of chance as you think.
- panarky 3y ago
  Huh? Snapchat uses TLS encryption for all data in transit, regardless of whether it's text, photos, or videos. This means that all forms of data are encrypted when they are being transmitted between your device and Snapchat's servers.
  - dogma1138 3y ago
    No E2EE means that they are able to look into messages, and unless they are doing key pinning which isn’t a given also susceptible to MITM.
    - panarky 3y ago
      "does not encrypt" != "No E2EE"
      - dogma1138 3y ago
        When you are talking about message encryption it’s rather clear, transport encryption can happen regardless of message encryption and overall is more easily defeated.
    - davidbanham 3y ago
      I think you’re confusing transport layer security with end to end encryption. TLS prevents the people who run Gatwick airport wifi from reading the messages. E2EE would also do that, and would additionally prevent Snapchat themselves from reading the messages. The lack of E2EE does not imply a lack of TLS.
      - dogma1138 3y ago
        I am not, no E2EE means that Snapchat can view text messages, hopefully the endpoint does use TLS but even if they do you assume that there is no MITM throughout the chain at all and that the app employs public key pinning to detect such attempts.
        davidbanham 3y ago
        That kind of an MITM attack would require both a lack of public key pinning from Snapchat _and_ a compromised certificate authority issuing bogus Snapchat TLS certificates that were trusted by common consumer devices. It's possible for a state level actor, sure, but it's unlikely that kind of countermeasure is being deployed in a blanket over every device connected to the Gatwick airport wifi. The parent post said (emphasis mine): > While everything was *TLS* encrypted between all conversation participants and the Snapchat server To which you replied: > Snapchat *does not encrypt* text messages only photos and video. Which isn't true. TLS is encryption, and provides effective protection against an MITM attack from the provider of the Gatwick airport wifi. Sure, E2EE encryption may provide better privacy. It's only providing a meaningful improvement against a certain group of adversaries, though. That's the set of attackers who have the resources to defeat TLS, even without public key pinning, yet who do not have the resources to compromise/keylog one or more of the devices or compel cooperation from Snapchat. Even if Snapchat did E2EE their messages, you would be very unlikely to have certainty that _your_ messages were secure. All it takes is `shouldE2EE := username != 'dogma1137'`. Or more likely `shouldCCTheNSA := username == 'dogma1137'`. The only defence against that kind of coerced cooperation is a full source code audit, confidence that there's no obfuscated code fooling your auditor, reproducible builds of the app, an ongoing assurance of some kind that the installed build's checksum matches that of the audited code, and finally full and ongoing confidence that none of the other vendors involved in the production of your device from the OS software stack right down to the baseband chip, have been similarly coerced. tl:dr, TLS is probably all you need. For the cases where TLS legitimately isn't sufficient, you should be assuming that any conversation within 100m of any electronic device has been compromised.
panarky 3y ago
> Most likely scenario ... That doesn't seem at all likely. Occam's Razor prefers explanations constructed with the smallest possible set of elements. In this case, that would be someone in the airport reading his screen and turning him in, or someone in his private chat turning him in.
- martinflack 3y ago
  And in this scenario, it might not even have been an assessment of risk, but rather "just to mess with him". The reporting person may have thought it would be a funny prank to have him questioned by police over the message and that would be the end of it.
- g-b-r 3y ago
  It doesn't seem so likely that a human in the airport happened to read his message, or that surveillance cameras at that airport OCR all peoples' phones (although I wouldn't be completely surprised if they did)
gmerc 3y ago
I’d imagine sending the message from an airport wifi IP would get it priority .
ngu_khoi 3y ago
No

whatshisface 3y ago

You seem to know a lot about security for someone with no interest in evading it. Good luck with your lottery ticket...

dogma1138 3y ago

Snapchat does not encrypt text messages only photos and video. Also the question of how many of those joke messages are being sent from an airport and have account meta data that can be tied to travel information (name, email, phone number). I wager far fewer that it may not make it into as much of a game of chance as you think.

panarky 3y ago
Huh? Snapchat uses TLS encryption for all data in transit, regardless of whether it's text, photos, or videos. This means that all forms of data are encrypted when they are being transmitted between your device and Snapchat's servers.
- dogma1138 3y ago
  No E2EE means that they are able to look into messages, and unless they are doing key pinning which isn’t a given also susceptible to MITM.
  - panarky 3y ago
    "does not encrypt" != "No E2EE"
    - dogma1138 3y ago
      When you are talking about message encryption it’s rather clear, transport encryption can happen regardless of message encryption and overall is more easily defeated.
  - davidbanham 3y ago
    I think you’re confusing transport layer security with end to end encryption. TLS prevents the people who run Gatwick airport wifi from reading the messages. E2EE would also do that, and would additionally prevent Snapchat themselves from reading the messages. The lack of E2EE does not imply a lack of TLS.
    - dogma1138 3y ago
      I am not, no E2EE means that Snapchat can view text messages, hopefully the endpoint does use TLS but even if they do you assume that there is no MITM throughout the chain at all and that the app employs public key pinning to detect such attempts.
      - davidbanham 3y ago
        That kind of an MITM attack would require both a lack of public key pinning from Snapchat _and_ a compromised certificate authority issuing bogus Snapchat TLS certificates that were trusted by common consumer devices. It's possible for a state level actor, sure, but it's unlikely that kind of countermeasure is being deployed in a blanket over every device connected to the Gatwick airport wifi. The parent post said (emphasis mine): > While everything was *TLS* encrypted between all conversation participants and the Snapchat server To which you replied: > Snapchat *does not encrypt* text messages only photos and video. Which isn't true. TLS is encryption, and provides effective protection against an MITM attack from the provider of the Gatwick airport wifi. Sure, E2EE encryption may provide better privacy. It's only providing a meaningful improvement against a certain group of adversaries, though. That's the set of attackers who have the resources to defeat TLS, even without public key pinning, yet who do not have the resources to compromise/keylog one or more of the devices or compel cooperation from Snapchat. Even if Snapchat did E2EE their messages, you would be very unlikely to have certainty that _your_ messages were secure. All it takes is `shouldE2EE := username != 'dogma1137'`. Or more likely `shouldCCTheNSA := username == 'dogma1137'`. The only defence against that kind of coerced cooperation is a full source code audit, confidence that there's no obfuscated code fooling your auditor, reproducible builds of the app, an ongoing assurance of some kind that the installed build's checksum matches that of the audited code, and finally full and ongoing confidence that none of the other vendors involved in the production of your device from the OS software stack right down to the baseband chip, have been similarly coerced. tl:dr, TLS is probably all you need. For the cases where TLS legitimately isn't sufficient, you should be assuming that any conversation within 100m of any electronic device has been compromised.

panarky 3y ago

> Most likely scenario ... That doesn't seem at all likely. Occam's Razor prefers explanations constructed with the smallest possible set of elements. In this case, that would be someone in the airport reading his screen and turning him in, or someone in his private chat turning him in.

martinflack 3y ago
And in this scenario, it might not even have been an assessment of risk, but rather "just to mess with him". The reporting person may have thought it would be a funny prank to have him questioned by police over the message and that would be the end of it.
g-b-r 3y ago
It doesn't seem so likely that a human in the airport happened to read his message, or that surveillance cameras at that airport OCR all peoples' phones (although I wouldn't be completely surprised if they did)

gmerc 3y ago

I’d imagine sending the message from an airport wifi IP would get it priority .

ngu_khoi 3y ago